tutanota/src/api/main/EventController.ts

import {downcast, identity, isSameTypeRefByAttr, noOp, remove, TypeRef} from "@tutao/tutanota-utils"
import type {LoginController} from "./LoginController"
import type {OperationType} from "../common/TutanotaConstants"
import stream from "mithril/stream"
import Stream from "mithril/stream"
import {assertMainOrNode} from "../common/Env"
import {EntityUpdate, WebsocketCounterData} from "../entities/sys/TypeRefs"

assertMainOrNode()
export type EntityUpdateData = {
	application: string
	type: string
	instanceListId: string
	instanceId: string
	operation: OperationType
}
export type EntityEventsListener = (updates: ReadonlyArray<EntityUpdateData>, eventOwnerGroupId: Id) => Promise<any>
export const isUpdateForTypeRef = <T>(typeRef: TypeRef<T>, update: EntityUpdateData): boolean => isSameTypeRefByAttr(typeRef, update.application, update.type)

export class EventController {
	private countersStream: Stream<WebsocketCounterData> = stream()
	private entityListeners: Array<EntityEventsListener> = []

	constructor(
		private readonly logins: LoginController
	) {
	}

	addEntityListener(listener: EntityEventsListener) {
		this.entityListeners.push(listener)
	}

	removeEntityListener(listener: EntityEventsListener) {
		remove(this.entityListeners, listener)
	}

	getCountersStream(): Stream<WebsocketCounterData> {
		// Create copy so it's never ended
		return this.countersStream.map(identity)
	}

	notificationReceived(entityUpdates: ReadonlyArray<EntityUpdate>, eventOwnerGroupId: Id): Promise<void> {
		let loginsUpdates = Promise.resolve()

		if (this.logins.isUserLoggedIn()) {
			// the UserController must be notified first as other event receivers depend on it to be up-to-date
			loginsUpdates = this.logins.getUserController().entityEventsReceived(entityUpdates as ReadonlyArray<EntityUpdateData>, eventOwnerGroupId)
		}

		return loginsUpdates
			.then(async () => {
				// sequentially to prevent parallel loading of instances
				for (const listener of this.entityListeners) {
					let entityUpdatesData: Array<EntityUpdateData> = downcast(entityUpdates)
					await listener(entityUpdatesData, eventOwnerGroupId)
				}
			})
			.then(noOp)
	}

	counterUpdateReceived(update: WebsocketCounterData) {
		this.countersStream(update)
	}
}